The Russian system was pitted against various aerial targets with small radar cross-section, including a ballistic missile, which the S-300 “smashed,” according to Air Defense Commander Brigadier General Farzad Esmaili. The Iranian military also ran a simulation of electronic warfare countermeasures to test the ability of the S-300 to lock on targets in difficult conditions.

Tehran and Moscow signed a contract for the S-300 in 2007, but it was suspended in 2010 after the UN Security Council passed a resolution banning the sale of advanced weapons to the Islamic Republic.

The restriction was lifted last year after Iran and six leading world powers signed a deal addressing concerns over Iran’s nuclear program. The development allowed Russia and Iran to renegotiate the terms of the almost decade-old contract, resolving a dispute over its suspension.

Iran insists that its acquisition and development of better weapons like the S-300 is necessary to protect itself from potential military aggression. Tehran’s long-standing regional rivals include Israel and Saudi Arabia.